Hello Im new in this Forum. And i read that you can put an Crossflow head on an older 8v engine. So i know the 2l 8v head from the mk4 head need some work on it to fit to the older block. But do the 1,6l mk4 8V head also fit ? And so far i now the holes for the big Head bolts need to be made bigger. And the Oil drain need some work. what exactly has to be changed ?
Ok. So IIRC theres 2 main version of crossflow head, for the ABA type casting its a straight fit on euro 2.0 8v blocks as same size bolts used and US MK3 2.0 block = Euro 2.0 block. However they have an elongated oil drain hole at the front, for early type blocks this is a problem as they only have a round casting here so you need to do a little work to fix that. Later casting i.e. MK3 2.0 8v blocks have the same shape cast and so, no problem. It's possible earlier versions of the 2E block have the early casting such as from Passat but not 100%. Anyway, heres piccies. Early casting, round casting at drain hole bottom left: 2.0 8v, elongated casting around the drain bottom left: I'm not 100% but I think MK4 crossflow head needs something blocking off round the back, plus head bolt holes elongating as you say becasue mk4 uses M10 bolts and MK1/2/3 M11. Have had a good look thru google images at various MK4 heads and it does look like its same basic cast as the ABA at the bottom just with smaller holes... But not had a cylinder head on my bench in person to check so dont take my word for that
think the later mk3 cabrio have them? not a huge expert but I think best bet is grab a mk4 golf one and have a look see how you go. tbh not really worth it imo just go 16v instead be cheaper in the long run after all the faffing about